1,721,207 research outputs found
No evidence for lipid A in Wolbachia: who is responsible for LPS-like activity in filarial nematodes?
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Preliminary results on the effect of tetracycline on the embryogenesis and symbiotic bacteria (Wolbachia) of Dirofilaria immitis. An update and discussion.
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Does fertilization in the filarial nematode Dirofilaria immitis occur through endocytosis of spermatozoa?
No full textIntramitochondrial bacteria in ticks and host-microbe interactions
No full textTicks are amongst the most important vectors of infectious diseases
of medical and veterinary importance, being present from
tropical to temperate areas and being capable of transmitting
viruses, bacteria, protozoa and even nematodes. PCR using universal
16S rRNAprimers followed by cloning and sequencing led
to detection of a novel alpha-proteobacterium in the hard tick
Ixodes ricinus, which has recently been named Midichloria mitochondrii.
Electron microscopy showed that M. mitochondrii
resides in the mitochondria of infected tick cells. The
discovery of a bacterium residing in mitochondria opens
the question of whether Midichloria causes damage to the host.
The damage, if any, is probably not very important. Indeed, the
prevalence of M. mitochondrii in wild populations of I. ricinus is
(or is very close to) 100% in females, which suggests that the
fitness of infected females is certainly not seriously reduced.
However, electron microscopy clearly shows that M. mitochondrii
leads to the consumption of infected mitochondria. In addition,
there is evidence that bacterial load and prevalence decrease
along generations in lab colonies of I. ricinus. Finally, infection
prevalence in adult male ticks collected in the wild is around 50%,
with low bacterial load in infected male individuals. The kind of
the interaction between M. mitochondrii and its host is probably
not easy to classify. Low prevalence in males seems to suggest
that the bacterium is not useful to individuals of this sex
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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